"FT 130 MOULDING HANDS Monaxite has a resinous to vitreous lustre*, and is translucent to sub-transparent. It is brittle, with a conchoidal to uneven fracture and a hard- ness of 5 on Molls' scale ; it can readily be senitehcd by felspar (hardness f>) or quart/* (hardness 7) ; it has a high spceifie gravity (4-r>-r>-:*). Moiw/itc is chiefly used as a source of thoria and ccria for the. manufacture of mean- d e.seen t mantles.1 Monazitc is also used an a, source of cerium, lanthanum, and other rare, metals which when alloyed with iron possess the property of emitting a ilame of great brilliancy with little heat and smoke when, scratched with steel. AB the sparks produced readily ignite gases, tinder, alcohol-wicks, and explosives, the.se alloys are used commercially as substitutes for matches, etc,, and in military signalling. Moulding1 Sand is that used for casting metal articles in foundries and other works. Particulars of the requirements and use of moulding Band will ha found in Vol. II., Chapter VI. Table XX., due to Boswell, shows the* geological position <»f the most important moulding sands in this country. Mud in a fine-textured fragmental material formed in water, usually by fiuviatile action, and corresponds to the dust deposits formed on dry land, the only difference being that the former are wet and the latter dry. Muds are usually derived from fine fragmental material carried out into lakes or seas by river-action, sea-erosion, etc. They consist of minute particles of quart/., felspar, mica, and other minerals, together with a variable* pro-- portion of clay, organic matter, and. calcium carbonate. Various minerals are sometimes present in sufficient quantity to give the muds a characteristic colour, such as the black and the blue* muds of the Black Sea, which contain iron sulphide and bisulphide, precipitated from solution as a result of anaerobic bacterial action. Kin. 7.- Mona'/itc sum. 20. 1 A. von WelHbach patented tho UHO of thoria for nmntlf*K in vfQM found later that tho presence of 1 percent coria gavoa groat w Hl effect. if.